Quality control workshops in standardization of sperm concentration and motility assessment in multicentre studies

Semen quality has been reported to vary markedly between different regions. To properly assess the differences among countries a minimization of the variation among centres in the assessments of sperm quality is essential. We here report on the training and two subsequent follow-up workshops on assessments of sperm concentration and motility. A total of 26 fresh ejaculates were analysed by four persons who were collecting these data in a multicentre study on sperm quality. In addition, two trained technicians from one of the laboratories analysed the samples. At the first training workshop, the median coefficient of variation among centres in sperm concentration was 27.7%, but decreased markedly to 17.0% at the second workshop and 8.1% (p = 0.048) at the third workshop. The CV for evaluation of the proportion of progressive motile sperm decreased less and not statistically significant from 16.5 to 14.1% and 11.0% (p = 0.94). At the third workshop there were no statistical significant differences among centres in assessments of sperm concentration or motility (p > 0.57). Furthermore the coefficient of variation in assessments of sperm concentration and motility among centres were at the same level as between two trained technicians (p > 0.72). This study indicates that training and subsequent follow-up workshops can assure minimum variability among centres in assessments of sperm concentration and motility.